Numerical Study Of Flow And Heat Transfer Performances For The Main-Auxiliary Integrated Indirect Dry Cooling System

China is a country with serious water shortage in the world.Saving water and improving the utilization rate of water resources is an important way to solve the problem of water shortage in China.Indirect air-cooling technology for power plants uses air and heat exchangers to make power plant operation less dependent on water resources,and is widely used in the northern regions of China where water resources are scarce.As an important cooling system for power plants,the auxiliary cooling system is the key to ensure the reliable operation of auxiliary equipment.The integration of auxiliary cooling water into the main cooling system is a combined innovative solution,which is named as the main and auxiliary combined indirect cooling system.This innovative cooling system has the advantages of centralized arrangement of cooling equipment,high land utilization,easy management and maintenance,saving the circulating water of auxiliary equipment and power consumption of fans,etc.Therefore,the main and auxiliary combined inderect cooling system has extensive application prospect.This paper focuses on the flow heat transfer characteristics of the combined main and auxiliary indirect air-cooling system under different configurations.Firstly,six physical models of combined indirect air-cooling system with double-layer arrangement of main and auxiliary radiators and single-layer arrangement,are established and termed as configuration A,B,C,D,E and F.The heat transfer area of main and auxiliary radiators,air-cooling tower,internal desulfurization tower and exhaust tower,are competely same for the six configurations.Secondly,the flow and heat transfer performances for different configurations of indirect air-cooling systems under TMCR and TRL 1 conditions,have been simulated and compared with Fluent.Finally,taking the configuration F as an example,the poor heat transfer performance of the laterally arranged auxiliary heat exchanger under ambient winds,has been sovled by installing wind breakers.The results show that,the system configuration has a much higher impact on the transport performance of the auxiliary cooling system than the main cooling system,and the flow performance is more likely to be affected than the heat transfer performance.In the absence of wind,the flow heat transfer performance of main and auxiliary cooling systems with double-layer arrangement is better than that of single-layer arrangement,and the cooling performance of configuration B is the best and that of configuration F is the worst for the main cooling system;the cooling performance of configuration A is the best and that of configuration E is the worst for the auxiliary cooling system.Under the design wind speed,for the main cooling system,the cooling performance of configuration E is the best and that of configuration C is the worst;for the auxiliary cooling system,the cooling performance of configuration C is the best and that of configuration E is the worst.As the ambient temperature rises,the heat transfer performance of the main and auxiliary cooling system decreases linearly,and the decline of the auxiliary cooling system is larger.The setting of the air retaining wall improves the heat transfer performance of the main and auxiliary cooling system of configuration F to a large extent,and can solve the problem of poor heat transfer performance when the fan area on the side of the auxiliary radiator is arranged.The research may provide theoretical guidance for the industrial design and application of the main and auxiliary combined indirect air cooling system.